<?php
/**
 * PHPExcel.
 *
 * Copyright (c) 2006 - 2014 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 *
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 *
 * @version    1.8.0, 2014-03-02
 */

/**
 * PHPExcel_Writer_Excel2007_Theme.
 *
 * @category   PHPExcel
 *
 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Writer_Excel2007_Theme extends PHPExcel_Writer_Excel2007_WriterPart
{
    /**
     * Map of Major fonts to write.
     *
     * @static	array of string
     */
    private static $_majorFonts = array(
                    'Jpan' => 'ＭＳ Ｐゴシック',
                    'Hang' => '맑은 고딕',
                    'Hans' => '宋体',
                    'Hant' => '新細明體',
                    'Arab' => 'Times New Roman',
                    'Hebr' => 'Times New Roman',
                    'Thai' => 'Tahoma',
                    'Ethi' => 'Nyala',
                    'Beng' => 'Vrinda',
                    'Gujr' => 'Shruti',
                    'Khmr' => 'MoolBoran',
                    'Knda' => 'Tunga',
                    'Guru' => 'Raavi',
                    'Cans' => 'Euphemia',
                    'Cher' => 'Plantagenet Cherokee',
                    'Yiii' => 'Microsoft Yi Baiti',
                    'Tibt' => 'Microsoft Himalaya',
                    'Thaa' => 'MV Boli',
                    'Deva' => 'Mangal',
                    'Telu' => 'Gautami',
                    'Taml' => 'Latha',
                    'Syrc' => 'Estrangelo Edessa',
                    'Orya' => 'Kalinga',
                    'Mlym' => 'Kartika',
                    'Laoo' => 'DokChampa',
                    'Sinh' => 'Iskoola Pota',
                    'Mong' => 'Mongolian Baiti',
                    'Viet' => 'Times New Roman',
                    'Uigh' => 'Microsoft Uighur',
                    'Geor' => 'Sylfaen',
            );

    /**
     * Map of Minor fonts to write.
     *
     * @static	array of string
     */
    private static $_minorFonts = array(
                    'Jpan' => 'ＭＳ Ｐゴシック',
                    'Hang' => '맑은 고딕',
                    'Hans' => '宋体',
                    'Hant' => '新細明體',
                    'Arab' => 'Arial',
                    'Hebr' => 'Arial',
                    'Thai' => 'Tahoma',
                    'Ethi' => 'Nyala',
                    'Beng' => 'Vrinda',
                    'Gujr' => 'Shruti',
                    'Khmr' => 'DaunPenh',
                    'Knda' => 'Tunga',
                    'Guru' => 'Raavi',
                    'Cans' => 'Euphemia',
                    'Cher' => 'Plantagenet Cherokee',
                    'Yiii' => 'Microsoft Yi Baiti',
                    'Tibt' => 'Microsoft Himalaya',
                    'Thaa' => 'MV Boli',
                    'Deva' => 'Mangal',
                    'Telu' => 'Gautami',
                    'Taml' => 'Latha',
                    'Syrc' => 'Estrangelo Edessa',
                    'Orya' => 'Kalinga',
                    'Mlym' => 'Kartika',
                    'Laoo' => 'DokChampa',
                    'Sinh' => 'Iskoola Pota',
                    'Mong' => 'Mongolian Baiti',
                    'Viet' => 'Arial',
                    'Uigh' => 'Microsoft Uighur',
                    'Geor' => 'Sylfaen',
            );

        /**
         * Map of core colours.
         *
         * @static	array of string
         */
        private static $_colourScheme = array(
                    'dk2' => '1F497D',
                    'lt2' => 'EEECE1',
                    'accent1' => '4F81BD',
                    'accent2' => 'C0504D',
                    'accent3' => '9BBB59',
                    'accent4' => '8064A2',
                    'accent5' => '4BACC6',
                    'accent6' => 'F79646',
                    'hlink' => '0000FF',
                    'folHlink' => '800080',
            );

    /**
     * Write theme to XML format.
     *
     * @param PHPExcel $pPHPExcel
     *
     * @return string XML Output
     *
     * @throws PHPExcel_Writer_Exception
     */
    public function writeTheme(PHPExcel $pPHPExcel = null)
    {
        // Create XML writer
            $objWriter = null;
        if ($this->getParentWriter()->getUseDiskCaching()) {
            $objWriter = new PHPExcel_Shared_XMLWriter(PHPExcel_Shared_XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
        } else {
            $objWriter = new PHPExcel_Shared_XMLWriter(PHPExcel_Shared_XMLWriter::STORAGE_MEMORY);
        }

            // XML header
            $objWriter->startDocument('1.0', 'UTF-8', 'yes');

            // a:theme
            $objWriter->startElement('a:theme');
        $objWriter->writeAttribute('xmlns:a', 'http://schemas.openxmlformats.org/drawingml/2006/main');
        $objWriter->writeAttribute('name', 'Office Theme');

                // a:themeElements
                $objWriter->startElement('a:themeElements');

                    // a:clrScheme
                    $objWriter->startElement('a:clrScheme');
        $objWriter->writeAttribute('name', 'Office');

                        // a:dk1
                        $objWriter->startElement('a:dk1');

                            // a:sysClr
                            $objWriter->startElement('a:sysClr');
        $objWriter->writeAttribute('val', 'windowText');
        $objWriter->writeAttribute('lastClr', '000000');
        $objWriter->endElement();

        $objWriter->endElement();

                        // a:lt1
                        $objWriter->startElement('a:lt1');

                            // a:sysClr
                            $objWriter->startElement('a:sysClr');
        $objWriter->writeAttribute('val', 'window');
        $objWriter->writeAttribute('lastClr', 'FFFFFF');
        $objWriter->endElement();

        $objWriter->endElement();

                        // a:dk2
                        $this->_writeColourScheme($objWriter);

        $objWriter->endElement();

                    // a:fontScheme
                    $objWriter->startElement('a:fontScheme');
        $objWriter->writeAttribute('name', 'Office');

                        // a:majorFont
                        $objWriter->startElement('a:majorFont');
        $this->_writeFonts($objWriter, 'Cambria', self::$_majorFonts);
        $objWriter->endElement();

                        // a:minorFont
                        $objWriter->startElement('a:minorFont');
        $this->_writeFonts($objWriter, 'Calibri', self::$_minorFonts);
        $objWriter->endElement();

        $objWriter->endElement();

                    // a:fmtScheme
                    $objWriter->startElement('a:fmtScheme');
        $objWriter->writeAttribute('name', 'Office');

                        // a:fillStyleLst
                        $objWriter->startElement('a:fillStyleLst');

                            // a:solidFill
                            $objWriter->startElement('a:solidFill');

                                // a:schemeClr
                                $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');
        $objWriter->endElement();

        $objWriter->endElement();

                            // a:gradFill
                            $objWriter->startElement('a:gradFill');
        $objWriter->writeAttribute('rotWithShape', '1');

                                // a:gsLst
                                $objWriter->startElement('a:gsLst');

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '0');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:tint
                                            $objWriter->startElement('a:tint');
        $objWriter->writeAttribute('val', '50000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '300000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '35000');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:tint
                                            $objWriter->startElement('a:tint');
        $objWriter->writeAttribute('val', '37000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '300000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '100000');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:tint
                                            $objWriter->startElement('a:tint');
        $objWriter->writeAttribute('val', '15000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '350000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                // a:lin
                                $objWriter->startElement('a:lin');
        $objWriter->writeAttribute('ang', '16200000');
        $objWriter->writeAttribute('scaled', '1');
        $objWriter->endElement();

        $objWriter->endElement();

                            // a:gradFill
                            $objWriter->startElement('a:gradFill');
        $objWriter->writeAttribute('rotWithShape', '1');

                                // a:gsLst
                                $objWriter->startElement('a:gsLst');

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '0');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:shade
                                            $objWriter->startElement('a:shade');
        $objWriter->writeAttribute('val', '51000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '130000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '80000');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:shade
                                            $objWriter->startElement('a:shade');
        $objWriter->writeAttribute('val', '93000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '130000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '100000');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:shade
                                            $objWriter->startElement('a:shade');
        $objWriter->writeAttribute('val', '94000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '135000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                // a:lin
                                $objWriter->startElement('a:lin');
        $objWriter->writeAttribute('ang', '16200000');
        $objWriter->writeAttribute('scaled', '0');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                        // a:lnStyleLst
                        $objWriter->startElement('a:lnStyleLst');

                            // a:ln
                            $objWriter->startElement('a:ln');
        $objWriter->writeAttribute('w', '9525');
        $objWriter->writeAttribute('cap', 'flat');
        $objWriter->writeAttribute('cmpd', 'sng');
        $objWriter->writeAttribute('algn', 'ctr');

                                // a:solidFill
                                $objWriter->startElement('a:solidFill');

                                    // a:schemeClr
                                    $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:shade
                                            $objWriter->startElement('a:shade');
        $objWriter->writeAttribute('val', '95000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '105000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                // a:prstDash
                                $objWriter->startElement('a:prstDash');
        $objWriter->writeAttribute('val', 'solid');
        $objWriter->endElement();

        $objWriter->endElement();

                            // a:ln
                            $objWriter->startElement('a:ln');
        $objWriter->writeAttribute('w', '25400');
        $objWriter->writeAttribute('cap', 'flat');
        $objWriter->writeAttribute('cmpd', 'sng');
        $objWriter->writeAttribute('algn', 'ctr');

                                // a:solidFill
                                $objWriter->startElement('a:solidFill');

                                    // a:schemeClr
                                    $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');
        $objWriter->endElement();

        $objWriter->endElement();

                                // a:prstDash
                                $objWriter->startElement('a:prstDash');
        $objWriter->writeAttribute('val', 'solid');
        $objWriter->endElement();

        $objWriter->endElement();

                            // a:ln
                            $objWriter->startElement('a:ln');
        $objWriter->writeAttribute('w', '38100');
        $objWriter->writeAttribute('cap', 'flat');
        $objWriter->writeAttribute('cmpd', 'sng');
        $objWriter->writeAttribute('algn', 'ctr');

                                // a:solidFill
                                $objWriter->startElement('a:solidFill');

                                    // a:schemeClr
                                    $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');
        $objWriter->endElement();

        $objWriter->endElement();

                                // a:prstDash
                                $objWriter->startElement('a:prstDash');
        $objWriter->writeAttribute('val', 'solid');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                        // a:effectStyleLst
                        $objWriter->startElement('a:effectStyleLst');

                            // a:effectStyle
                            $objWriter->startElement('a:effectStyle');

                                // a:effectLst
                                $objWriter->startElement('a:effectLst');

                                    // a:outerShdw
                                    $objWriter->startElement('a:outerShdw');
        $objWriter->writeAttribute('blurRad', '40000');
        $objWriter->writeAttribute('dist', '20000');
        $objWriter->writeAttribute('dir', '5400000');
        $objWriter->writeAttribute('rotWithShape', '0');

                                        // a:srgbClr
                                        $objWriter->startElement('a:srgbClr');
        $objWriter->writeAttribute('val', '000000');

                                            // a:alpha
                                            $objWriter->startElement('a:alpha');
        $objWriter->writeAttribute('val', '38000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                            // a:effectStyle
                            $objWriter->startElement('a:effectStyle');

                                // a:effectLst
                                $objWriter->startElement('a:effectLst');

                                    // a:outerShdw
                                    $objWriter->startElement('a:outerShdw');
        $objWriter->writeAttribute('blurRad', '40000');
        $objWriter->writeAttribute('dist', '23000');
        $objWriter->writeAttribute('dir', '5400000');
        $objWriter->writeAttribute('rotWithShape', '0');

                                        // a:srgbClr
                                        $objWriter->startElement('a:srgbClr');
        $objWriter->writeAttribute('val', '000000');

                                            // a:alpha
                                            $objWriter->startElement('a:alpha');
        $objWriter->writeAttribute('val', '35000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                            // a:effectStyle
                            $objWriter->startElement('a:effectStyle');

                                // a:effectLst
                                $objWriter->startElement('a:effectLst');

                                    // a:outerShdw
                                    $objWriter->startElement('a:outerShdw');
        $objWriter->writeAttribute('blurRad', '40000');
        $objWriter->writeAttribute('dist', '23000');
        $objWriter->writeAttribute('dir', '5400000');
        $objWriter->writeAttribute('rotWithShape', '0');

                                        // a:srgbClr
                                        $objWriter->startElement('a:srgbClr');
        $objWriter->writeAttribute('val', '000000');

                                            // a:alpha
                                            $objWriter->startElement('a:alpha');
        $objWriter->writeAttribute('val', '35000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                // a:scene3d
                                $objWriter->startElement('a:scene3d');

                                    // a:camera
                                    $objWriter->startElement('a:camera');
        $objWriter->writeAttribute('prst', 'orthographicFront');

                                        // a:rot
                                        $objWriter->startElement('a:rot');
        $objWriter->writeAttribute('lat', '0');
        $objWriter->writeAttribute('lon', '0');
        $objWriter->writeAttribute('rev', '0');
        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:lightRig
                                    $objWriter->startElement('a:lightRig');
        $objWriter->writeAttribute('rig', 'threePt');
        $objWriter->writeAttribute('dir', 't');

                                        // a:rot
                                        $objWriter->startElement('a:rot');
        $objWriter->writeAttribute('lat', '0');
        $objWriter->writeAttribute('lon', '0');
        $objWriter->writeAttribute('rev', '1200000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                // a:sp3d
                                $objWriter->startElement('a:sp3d');

                                    // a:bevelT
                                    $objWriter->startElement('a:bevelT');
        $objWriter->writeAttribute('w', '63500');
        $objWriter->writeAttribute('h', '25400');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                        // a:bgFillStyleLst
                        $objWriter->startElement('a:bgFillStyleLst');

                            // a:solidFill
                            $objWriter->startElement('a:solidFill');

                                // a:schemeClr
                                $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');
        $objWriter->endElement();

        $objWriter->endElement();

                            // a:gradFill
                            $objWriter->startElement('a:gradFill');
        $objWriter->writeAttribute('rotWithShape', '1');

                                // a:gsLst
                                $objWriter->startElement('a:gsLst');

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '0');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:tint
                                            $objWriter->startElement('a:tint');
        $objWriter->writeAttribute('val', '40000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '350000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '40000');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:tint
                                            $objWriter->startElement('a:tint');
        $objWriter->writeAttribute('val', '45000');
        $objWriter->endElement();

                                            // a:shade
                                            $objWriter->startElement('a:shade');
        $objWriter->writeAttribute('val', '99000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '350000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '100000');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:shade
                                            $objWriter->startElement('a:shade');
        $objWriter->writeAttribute('val', '20000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '255000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                // a:path
                                $objWriter->startElement('a:path');
        $objWriter->writeAttribute('path', 'circle');

                                    // a:fillToRect
                                    $objWriter->startElement('a:fillToRect');
        $objWriter->writeAttribute('l', '50000');
        $objWriter->writeAttribute('t', '-80000');
        $objWriter->writeAttribute('r', '50000');
        $objWriter->writeAttribute('b', '180000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                            // a:gradFill
                            $objWriter->startElement('a:gradFill');
        $objWriter->writeAttribute('rotWithShape', '1');

                                // a:gsLst
                                $objWriter->startElement('a:gsLst');

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '0');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:tint
                                            $objWriter->startElement('a:tint');
        $objWriter->writeAttribute('val', '80000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '300000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                    // a:gs
                                    $objWriter->startElement('a:gs');
        $objWriter->writeAttribute('pos', '100000');

                                        // a:schemeClr
                                        $objWriter->startElement('a:schemeClr');
        $objWriter->writeAttribute('val', 'phClr');

                                            // a:shade
                                            $objWriter->startElement('a:shade');
        $objWriter->writeAttribute('val', '30000');
        $objWriter->endElement();

                                            // a:satMod
                                            $objWriter->startElement('a:satMod');
        $objWriter->writeAttribute('val', '200000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                                // a:path
                                $objWriter->startElement('a:path');
        $objWriter->writeAttribute('path', 'circle');

                                    // a:fillToRect
                                    $objWriter->startElement('a:fillToRect');
        $objWriter->writeAttribute('l', '50000');
        $objWriter->writeAttribute('t', '50000');
        $objWriter->writeAttribute('r', '50000');
        $objWriter->writeAttribute('b', '50000');
        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

        $objWriter->endElement();

                // a:objectDefaults
                $objWriter->writeElement('a:objectDefaults', null);

                // a:extraClrSchemeLst
                $objWriter->writeElement('a:extraClrSchemeLst', null);

        $objWriter->endElement();

            // Return
            return $objWriter->getData();
    }

    /**
     * Write fonts to XML format.
     *
     * @param PHPExcel_Shared_XMLWriter $objWriter
     * @param string                    $latinFont
     * @param array of string           $fontSet
     *
     * @return string XML Output
     *
     * @throws PHPExcel_Writer_Exception
     */
    private function _writeFonts($objWriter, $latinFont, $fontSet)
    {
        // a:latin
        $objWriter->startElement('a:latin');
        $objWriter->writeAttribute('typeface', $latinFont);
        $objWriter->endElement();

        // a:ea
        $objWriter->startElement('a:ea');
        $objWriter->writeAttribute('typeface', '');
        $objWriter->endElement();

        // a:cs
        $objWriter->startElement('a:cs');
        $objWriter->writeAttribute('typeface', '');
        $objWriter->endElement();

        foreach ($fontSet as $fontScript => $typeface) {
            $objWriter->startElement('a:font');
            $objWriter->writeAttribute('script', $fontScript);
            $objWriter->writeAttribute('typeface', $typeface);
            $objWriter->endElement();
        }
    }

    /**
     * Write colour scheme to XML format.
     *
     * @param PHPExcel_Shared_XMLWriter $objWriter
     *
     * @return string XML Output
     *
     * @throws PHPExcel_Writer_Exception
     */
    private function _writeColourScheme($objWriter)
    {
        foreach (self::$_colourScheme as $colourName => $colourValue) {
            $objWriter->startElement('a:'.$colourName);

            $objWriter->startElement('a:srgbClr');
            $objWriter->writeAttribute('val', $colourValue);
            $objWriter->endElement();

            $objWriter->endElement();
        }
    }
}
